• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.996-1000
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• 2003

In this paper, Fly robot with electric power, a kind of Unmanned aerial vehicle (UAV), is considered as an autonomous hovering platform, capable of vertical lift-off, landing and stationary hovering. This aircraft has four rotor and DC motors of electrical Power, which is capable of omni-direction for indoor application. In the earlier days of vertical flight experimentation developers looked at the intuitively easy control functionality of 4 rotor designs. But we need to obtain design method of suitable structures and adequate components because the existing prototypes of 4 rotor-craft don't analyze the propeller, motor characteristic and propose a methodology to optimize this system. In this paper, we will show the new 4 rotor craft with blimp, analyze design and manufacturing method of 4 rotor craft system. Also we prove propriety of our design and manufacturing method by being based on thrust and motor experiment.

• Smart Structures and Systems
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• v.14 no.4
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• pp.541-558
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• 2014

This paper proposes a new design of shape memory alloy (SMA) wire actuated gripper for open mode operation. SMA can generate smooth muscle movements during actuation which make them potentially good contenders in designing grippers. The principle of the shape memory alloy gripper is to convert the linear displacement of the SMA wire actuator into the angular displacement of the gripping jaw. Steady state analysis is performed to design the wire diameter of the bias spring for a known SMA wire. The gripper is designed to open about an angle of $22.5^{\circ}$ when actuated using pulsating electric current from a constant current source. The safe operating power range of the gripper is determined and verified theoretically. Experimental evaluation for the uncontrolled gripper showed a rotation of $19.97^{\circ}$. Forced cooling techniques were employed to speed up the cooling process. The gripper is simple and robust in design (single movable jaw), easy to fabricate, low cost, and exhibits wide handling capabilities like longer object handling time and handling wide sizes of objects with minimum utilization of power since power is required only to grasp and release operations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.50-55
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• 1991

This paper presents database technique for an computer-integrated structural design system of buildings. Network database designed to support all the processes of structural design, such as, planning, modelling, analysis, member design and redesign processes etc. stores all information from user input and system results effectively and so provides centeral communication area between applications. The user interface wi th interactive and batch modes plays roles of building modeler including conventional pre-processor and post-processor. The concepts of 'Planar Surface Modeling' and 'Geometry Zoning' are defined for easy construction of building model. The concept presented in this paper will save the time and memory required for model generation and contribute to data consistency, thus leave a designer more time actually performing the analyses and interpreting the results. The formulation of automating the process of bulilding model ins and structural analysis is the key to study.

• Journal of Power System Engineering
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• v.18 no.5
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• pp.28-34
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• 2014

This paper deals with optimum PI controller design using genetic algorithm to improve control performance and robustness for an oil cooler system. The optimum PI gain was found to minimize an object function, integrated absolute error, and to satisfy control design specifications such as overshoot and settling time based on practical transfer function of the oil cooler system. The control performance and robustness were investigated by comparing indicial responses and Bode diagram analysis with respect to three kinds of PI gains obtained from different gain decision manners. Moreover, the robustness against to input disturbances, sinusoidal wave form and abrupt single pulse, was evaluated. The computer simulation results showed that the suggested optimum gain can establish desirable control performance and strong robustness with easy design process.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.270-274
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• 2001

Fans are widely used in household electrical appliances due to their easy usage and high performance for cooling capacity. However, the noise generated by these fans causes one of serious problems. LG electronics makes the intranet software for design and analysis of fan. Axial, sirocco and centrifugal fan can be designed and analyzed by using the IFD(Intranet Based Fans Design) software. In order to calculate the aeroacoustic noise of a fan, the numerical method, which can calculate the acoustic pressure at the blade passing frequency and its higher harmonic frequencies, has been developed. To calculate the unsteady resultant force of the blade, vortex method is used. This paper shows the overview of the software and validates the accuracy of predicted noise of fan.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.165-168
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• 2001

This Paper presents the design method and performance characteristics of a dual band balun. The design method for dual balun is based on the lumped element eqiuvalent circuit of quater-wave transformaer. By employing the proposed configuration and the derived formulas, dual band balun are designed and simulated and manufactured. The proposed design method and equivalent circuit can make it easy to adapt to designing of ceramic multi-layer chip type dual band balun. The dual band will find applications in wireless communication circuits.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.3
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• pp.328-336
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• 2008

This research proposes a method for economic-statistical design of adaptive moving average (A-MA) charts. The basic idea of the A-MA chart is to accumulate previous samples selectively in order to increase the sensitivity. The A-MA chart is a kind of adaptive chart such as the variable sampling size (VSS) chart. A major advantage of the A-MA chart over the VSS chart is that it is easy to maintain rational subgroups by using the fixed sampling size. A steady state cost rate function is constructed based on Lorenzen and Vance (1986) model. The cost rate function is optimized with respect to five design parameters. Computational experiments show that the A-MA chart is superior to the VSS chart as well as to the Shewhart $\bar{X}$ chart in the economic-statistical sense.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.63-68
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• 2015

Pattern layout design is very important to the automation of apparel industry. Until now, the genetic algorithm and Tabu search method have been applied to layout design automation. With the genetic algorithm and Tabu search method, the obtained values are not always consistent depending on the initial conditions, number of iterations, and scheduling. In addition, the selection of various parameters for these methods is not easy. This paper presents a hybrid search method that uses a neural network and simulated annealing to solve these problems. The layout of pattern elements was optimized to verify the potential application of the suggested method to apparel pattern layout design.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.10
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• pp.407-417
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• 1985

This paper describes a new method for the design of adaptive model-following control systems. This design concept is developed using the theory of slide mode. Authors present new results on the sliding control methodology to achieve accurate tracking for a class of multi-input multi-output, time-varying systems in the presence of parameter variations and disturbances. This algorithm can be easily applied to the multivariable control systems and obtained a smoother control signal in comparison to variable structure model following control systems. The design technique is easy and the control structure is simple. The design requires little computational effort. The control system is less sensitive to plant parameter variations and noise disturbances.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.169-174
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• 2000

This paper is about automatic design of measuring master gears. Master gears are usually thought of as gears of extreme accuracy level, but are better defined as gages to check the meshing action of production gears. This is usually not recognized because most mechanical gages are associated with static measurements rather than having the form of machine elements used in a functional check involving machine motion. In this paper the interface that allows beginners to design easily and quickly is provided. The addition and modification of data is easy and the reduced design lead time is feasible with the program even though users don't know much about program since it is developed with Visual Lisp and DCL.